Seth Godin understands marketing. Marketing applies both in the business world and the political world. He has a very short essay on a fundamental truth about brand and political marketing. They are really only selling fear, hope, or love. Let me expand on that in the political realm.
Reformers often want to add a fourth concept in here - competence. That is wrong. People usually only vote for competence after experiencing incompetence and then fearing either a repeat or a continuation.
Conservatives have more things that they are fearful of and conservative campaigns usually seem based on fear. A conservative who adds hope to his fear campaign can be very sucessful - Reagan.
Liberals more than conservatives are often selling hope. I think they are more successful among people who fear a continuation of conservative policies that are hurting them or their family or their friends or their ideals. There can be a touch of love in their campaigns too. "I love people, or the environment, and this will help."
Libertarians are usually a version of fear. "I've got mine Jack" and the government shouldn't take it away. On social issues, libertarians fear other people or the government telling them what to do. There is a bit of hope that somehow this makes the world a better place. They are deluded that government is the main or only source of a loss of liberty.
Greens and other people on the far left love the Earth and people and sell the hope that working together we can help the Earth and people. There is also fear of corporations and conservatives and selfish bastards and what they are doing.
Moralists think they have the answer to all problems. They sell the hope of mandating everyone to follow their beliefs, the fear of the others who are the cause of evil, and/or the fear and hope of "end of days." There is a bit of love for people and not-yet-born-people who must be protected.
I recommend Seth's books. Food for thought even if you don't agree with him or think he is too simplistic. The books are not about politics but ideas and business.